Lock for knobs and the like

ABSTRACT

A lock for releasably securing a pushbutton, knob or the like to an actuator, such as a rod or shaft, comprising a member constructed of resilient metallic sheet material having prongs or barbs embedded into the knob for preventing its removal from same and including a resilient cantilevered locking lever having an aperture therein through which the rod extends which jams and frictionally engages the rod but which may be manually flexed to a release position. The increasing embedment or indentation of the knob by the prongs, with time and wear, is ineffective to change the resilient urge of the lever from its initial position of assembly, thereby maintaining the locking effect unchanged.

Hansen 1 llama L18, 1972 154} LOQM IF UR IMNUBS AND THE lsllllflli Wray Carl Hansen, 8755 West 73rd Place, Arvada, Colo. 80002 [22] Filed: June22,1970

21 Appl.No.: 48,068

[72] Inventor:

Primary Examiner-George F. Mautz Assistant ExaminerEdward J. McCarthy Att0rney Sheridan, Ross [57] ABSTRACT A lock for releasably securing a pushhutton, knob or the like to an actuator, such as a rod or shaft, comprising a member constructed of resilient metallic sheet material having prongs or barbs embedded into the knob for preventing its removal from same and including a resilient cantilevered locking lever having an aperture therein through which the rod extends which jams and frictionally engages the rod but which may be manually flexed to a release position. The increasing embedment or indentation of the knob by the prongs, with time and wear, is ineffective to change the resilient urge of the lever from its initial position of assembly, thereby maintaining the locking effect unchanged.

10 Claims, 9 Drawing lFigures Pmmmmmm 3.635.512

INVENTOR WRAY c. HANSEN ATTORNEYS ll LOCK roa KNOBS AND run Links BACKGROUND OF THE INVENTION In the art of fastening manual control members, such as pushbuttons, knobs, dials, handles, and the like, to shafts or rods, it has been the practice to employ resilient fasteners which interlock the parts in various manners to secure them together. Usually, they may also be released to permit removal of the manual member from the rod or shaft to facilitate assembly or disassembly of other parts with which the member is associated. Push button radios, other electrical devices, and household appliances are exemplary of but a few of the myriad applications of such devices. The manual members are often formed from nonmetallic materials, such as plastics, and the like, which may be moulded in dies with the attendant minimization of cost of manufacture. Since such materials are relatively soft, compared with metals, difficulties have been experienced in constructing satisfactory fasteners or locks, particularly where they employed locking prongs or barbs which embedded into the softer material. In one prior construction, for example, and over which the present invention constitutes an improvement, the prongs continued to deepen their embedment into the soft manual member and during this contained deepening of embedment the lock with the rod or shaft became less effective.

SUMMARY OF THE INVENTION A lock for releasably securing a pushbutton, knob or the like to its actuating shaft or rod characterized by a member formed from flat metallic spring material having resilient prongs slidable into slots or recesses in the knob which engage and indent the knob to prevent removal of same, further characterized by a cantilevered and apertured arm which engages the rod and frictionally engages and jams same to prevent undesired removal but permits removal by manually moving the cantilevered arm to a release position. The orientation of the prongs relative to the knob is such that upon continued indentation or embedment of the knob by the prongs the arm maintains substantially the same locking force on the rod.

It is thus a principal object of the present invention to provide a locking device, particularly for use with relatively soft knobs and the like, which retains its optimum locking action to the rod regardless of changes of orientation of its parts resulting from progressive and increasing embedment of its locking prongs or barbs.

Further objects, advantages, and salient features will become more apparent from the detailed description to follow, the appended claims, and the accompanying drawing to now be briefly described.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a plan of a spring lock for securing a knob to a shaft;

FIG. 2 is a side elevation and partial section taken on line 2-2, FIG. 1;

FIG. 3 is an end elevation as viewed in the direction of arrow 3, FIGS. 1 and 2;

FIG. 4 is an end elevation of a knob as viewed in the direction of arrow 4, FIG. 5;

FIG. 5 is a section taken on line 5-5, FIG. 4;

FIG. 6 is a side elevation and section, like FIG. 2, illustrating a shaft and lock in locked relationship;

FIG. 7 is a side elevation and section, like FIG. 6, after assembly into the knob, also illustrating a tool for removing the knob; and

FIGS. 8 and 9 are sections of alternative forms of actuator rods.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings, the subject of the invention comprises, briefly, a spring lock L for securing a knob K to a shaft or rod R which may be of various cross sections, the assembly of the three parts being illustrated in FIG. 7 wherein rod R is rectangular.

As best illustrated in FIG. 4, the knob is provided with an inverted T-slot 10 having a rectangular portion 12 and a pair of rectangular wing portions 14,14 joining same and projecting outwardly therefrom. A recess 16, somewhat larger than the lslot, is provided at the open end of the knob which receives a portion of lock L to be subsequently described in detail. A notch 18 in the wall of the knob provides access to the lock for removing the knob from the shaft, the manner of which will also be subsequently described.

Referring now to FIGS. 1 to 3, the lock comprises a spring metal member, such as spring steel, spring bronze, or the like, which is formed from flat stock by conventional blanking, punching and bending operations. It comprises a flat base portion 19 having an upturned tab or abutment 20 at one end and a pair of upturned barbs or prongs 22,22 adjacent opposite lateral edges of same. Near the other end, the base portion is joined to a downwardly extending U-shaped neck portion 23, serving as a spring, the outer free leg 24 of which is disposed angularly to the base member and provided with a rectangular aperture 26, having dimensions to permit rod R to slide through the aperture, preferably with small clearance, particularly with respect to the thickness or narrow dimension of the rectangular rod.

Referring now to FIG. 6, which illustrates rod R locked to lock L, the lower surface of the rod is in facial engagement with base 19 and leg 24 has been rotated slightly in a counterclockwise direction from its relaxed position so that the clockwise moment on leg 24 jams the upper and lower edges of aperture 26 into locking engagement with the rod. This results since in the relaxed position of lock L the lower edge of aperture 26 is displaced slightly to one side of the plane of base portion 19. Due to the angularity of leg 24 to base portion 19, the tendency for leg 24 to rotate clockwise reduces, in effect, the vertical distance between the lower and upper edges of aperture 24. Conversely, when arm 24 is manually rotated in a counterclockwise direction, the vertical distance is increased, unlocking the edges of aperture 26 from engagement with the rod. A locking action may be attained by displacing the lower edge of aperture 24, relative to the plane of the top surface of base portion 19, in a direction below or above same. Displacement in a direction above the plane, however, is preferred since this has been found to produce the more desirable locking and unlocking action. FIG. 7 illustrates the same relationship of parts as FIG. 6 but with lock L locked to knob l(. The dotted position of arm 24 illustrates the manual counterclockwise movement to unlocked position, referred to.

The height of upturned prongs 22 is such that when they enter slots 14,14 they are sprung slightly so that their free ends resiliently engage surfaces 30,30 of slots 14,14, resisting removal. If the knob is constructed of relatively soft material, such as plastic, the prongs form slight indentations in these surfaces forming a permanent lock of the spring lock to the knob.

The importance of disposing barbs 22 in the position disclosed can be better understood by reference again to FIG. 7. In the position shown, U-shaped portion 23 is under a counterclockwise moment, due to flexure of spring 23 from its previous position, as shown in FIG. 6. This rotates the lower face of base 19 into tight facial engagement with the surface 32 which it abuts. Since there are no prongs or barbs extending from the lower face there cannot be any embedment which would permit it to change position, hence leg 24 also is permanently retained in its initial position. In contrast, if the prongs projected from the lower face, they would continue to embed into the soft knob, permitting the base 19 to rotate counterclockwise, which as will be apparent, would change the initial angle of assembly between the base llSl and leg 24 thus reducing the moment and reducing the locking action between the leg and actuating rod.

The knob and its attached spring lock may be removed from the rod, when desired, by straining leg 24 in the direction opposite to the direction in which ittends to move. Thus, by inserting a hook shaped tool T into notch 18 and engaging the free end ofleg24 it may be moved to the dotted position of FIG. 7, releasing its engagement with the rod. As soon as it is released, continuation of the pull on leg 24 slides the knob and spring assembly along the rod to a disconnected position.

As so far described, rod R is rectangular in cross section, this being a common expedient when it can be readily punched from flat stock. The cross section may be otherwise; however, FIG. 8 illustrating a rod R which is constructed from round stock with a flat on same and FIG. 9 illustrating a rod R of triangular shape. As will be apparent, aperture 26 will then be punched to a corresponding shape and recess 12 similarly formed to receive the rod and spring lock.

What is claimed is:

l. A knob lock for securing a knob having an open-ended longitudinally extending noncircular aperture of substantially uniform cross section, to an end of a rod having a corresponding cross section, by relative axial movement between the knob and rod, said aperture being disposed between a pair of longitudinally extending channels in the knob, one on each side of said aperture and communicating therewith, one wall of said channels and one wall of said aperture being disposed in substantially the same plane, forming a common wall, said channels each having another wall disposed in spaced relation to said common wall, forming locking walls, said knob lock comprising:

a. an integral member formed from resilient metallic sheet material by blanking, shearing and bending operations;

b. said member comprising a flat base portion having one face adapted to abut said common wall, the central portion of its other face adapted to be disposed adjacent and parallel to a flat portion on the rod;

c. at least one prong adjacent each lateral edge of the base portion, sheared and bent at an acute angle away from the plane of the base portion, its free end being pointed in a directiontoward the open end of the knob aperture and having a right angular corner adapted to resiliently engage the corresponding locking wall adjacent thereto for preventing separation of the member from the knob and for urging said one face into engagement with said common wall; and

d. a terminal leg extending from one end of said base member having an aperture therein corresponding to the cross section of the rod and through which the rod is adapted to extend, for releasably securing the terminal leg to the rod.

2. A knob lock in accordance with claim 1 wherein the aperture in the terminal leg is rectangular.

3. A knob lock in accordance with claim 1 wherein the aperture in the terminal leg is isoceles triangular.

4. A knob lock is accordance with claim 1 wherein the aperture in the terminal leg is circular with a chordal flat portion.

5. A knob lock in accordance with claim 1 in combination with said knob and rod.

6. The combination of claim 5 wherein the aperture in the terminal leg and in the knob are rectangular.

7. The combination of claim 5 wherein the aperture in the terminal leg and in the knob are isoceles triangular.

8. The combination of claim 5 wherein the aperture in the terminal leg and in the knob are circular with a chordal flat portion.

9. A knob lock in accordance with claim 1 including at least two like prongs spaced along each lateral edge of the base portion.

10. A knob lock in accordance with claim 1 including a tab at the inner end of the base portion, bent away from its plane to substantially a right angle, its free end terminating at a position within said aperture and in nonlocking engagement therewith, forming an abutment for inserting the lock into the knob, said prongs formipg the s olelock therewith. 

1. A knob lock for securing a knob having an open-ended longitudinally extending noncircular aperture of substantially uniform cross section, to an end of a rod having a corresponding cross section, by relative axial movement between the knob and rod, said aperture being disposed between a pair of longitudinally extending channels in the knob, one on each side of said aperture and communicating therewith, one wall of said channels and one wall of said aperture being disposed in substantially the same plane, forming a common wall, said channels each having another wall disposed in spaced relation to said common wall, forming locking walls, said knob lock comprising: a. an integral member formed from resilient metallic sheet material by blanking, shearing and bending operations; b. said member comprising a flat base portion having one face adapted to abut said common wall, the central portion of its other face adapted to be disposed adjacent and parallel to a flat portion on the rod; c. at least one prong adjacent each lateral edge of the base portion, sheared and bent at an acute angle away from the plane of the base portion, its free end being pointed in a direction toward the open end of the knob aperture and having a right angular corner adapted to resiliently engage the corresponding locking wall adjacent thereto for preventing separation of the member from the knob and for urging said one face into engagement with said common wall; and d. a terminal leg extending from one end of said base member having an aperture therein corresponding to the cross section of the rod and through which the rod is adapted to extend, for releasably securing the terminal leg to the rod.
 2. A knob lock in accordance with claim 1 wherein the aperture in the terminal leg is rectangular.
 3. A knob lock in accordance with claim 1 wherein the aperture in the terminal leg is isoceles triangular.
 4. A knob lock is accordance with claim 1 wherein the aperture in the terminal leg is circular with a chordal flat portion.
 5. A knob lock in accordance with claim 1 in combination with said knob and rod.
 6. The combination of claim 5 wherein the aperture in the terminal leg and in the knob are rectangular.
 7. The combination of claim 5 wherein the aperture in the terminal leg and in the knob are isoceles triangular.
 8. The combination of claim 5 wherein the aperture in the terminal leg and in the knob are circular with a chordal flat portion.
 9. A knob lock in accordance with claim 1 including at least two like prongs spaced along each lateral edge of the base portion.
 10. A knob lock in accordance with claim 1 including a tab at the inner end of the base portion, bent away from its plane to substantially a right angle, its free end terminating at a position within said aperture and in nonlocking engagement therewith, forming an abutment for inserting the lock into the knob, said prongs forming the sole lock therewith. 